By Nari Nayini, Ph.D – Food and Cannabis Consultant
Chemical Residues
There are currently no chemical pesticides approved for use on cannabis in California. The Bureau of Cannabis Control (BCC) has set zero tolerance limits for 21 ‘higher risk’ Category I pesticides and challenging action levels for 45 additional ‘lower risk’ Category II pesticides.
This can prove challenging to cannabis cultivators and manufacturers for a number of reasons. First, cannabis is susceptible to ‘pests’ including mites, aphids, fungi, and microbial organisms. Chemical pesticides are the easiest means to control for these pests and prevent the economic losses they can cause. Second, low levels of many of these pesticides are present in the environment as a result of drift, prior land use, or material inputs like fertilizer. Even if they are absorbed into the plant at passable levels, the process of extracting cannabinoids can also concentrate pesticides, resulting in failing product. Third, foods used in edibles often have approved pesticide usages and can be sources of contamination themselves.
The California Department of Pesticide Regulation (DPR) does permit the usage of certain natural pesticides that are exempt from residual tolerance and/or registration requirements. During growing, trained personnel should follow standard operating procedures for preparing and applying recommended concentrations of these pesticides.
Precautions should be taken during the production process, packaging and storage to avoid accidental introduction of chemicals. Once cannabis products are harvested, chemical controls must be in place to avoid accidental contamination. All chemicals should be labelled and stored in contained chemical storage. Only food-grade chemicals (e.g. cleaners, sanitizers) should be used during growing, harvesting, curing, drying, trimming and storage.
Last, all new food inputs should be tested prior to usage in commercial production and be monitored on a semi-regular basis.
Mold Growth (Aflatoxins)
Improper growing conditions, handling and storage can result in mold growth, which produce aflatoxins that are known to cause liver cancer and other health problems.
Humidity should be monitored and controlled during growing and storage. Those humidity meters in storage should be monitored at least twice per day and receive calibration on a monthly basis. During transportation, the temperature of the truck should be monitored and recorded.
Transport truck trailers should be cleaned and disinfected with appropriate, approved chemicals. Products received at a cannabis facility should be tested upon arrival and contaminated products should be rejected, segregated and disposed of safely.
Pathogenic Contamination
Water is essential for robust growth, but it also can act as a carrier for pathogenic bacteria like E. coli, Staphylococcus or Salmonella. For this reason, it is recommended that filtered city water be utilized, and that the facility monitor the municipal water test reports regularly. If facilities are using well water, samples should be tested at minimum every three months and implement corrective measures if it’s out of specification.
A facility pest control program should be implemented in order to prevent infestations from insects, rodents and other pests with traps. These should be checked monthly by a qualified contractor and verified by a trained employee. A written building inspection procedure, particularly relating to the drying process area, should include a monthly check, with no holes or gaps allowed outside the facility. Product should only leave the facility in proper packages to prevent fecal matter and other hazards from coming into contact with cannabis products.
Facilities should have written Good Manufacturing Practices (GMP) and personal hygiene policies in place. All personnel should be trained on these practices and procedures upon hiring and refreshed on a regular basis. Retraining should also occur if any changes are made to production lines or processes.
Employees should be instructed to wear proper gear (gloves, hair nets, etc.) while working, and glass, jewelry and outside food should not be allowed into the production areas. Tools used in cultivating, harvesting and processing can carry microbial pathogens so employees must be trained in effective cleaning procedures.
The Future
Cannabis companies should plan to implement comprehensive safety programs similar to those implemented by the food industry that include procedures, training, monitoring and verification to prevent food safety hazards.
It is possible that other food safety issues like packaging safety (inks and labels), allergens, nutritional content, adulteration, and counterfeiting will also be areas of concern for the cannabis industry in the future. The good news is they will have a model with which to deal with these hazards.
